As IP (Internet Protocol) network equipment, such as routers and switches become more powerful, the need for value-added services on these equipments is increasing. The type of services which may be enabled depends on performance issues, availability of hardware to support meaningful services, and a need for such services. Based on these constraints, one promising feature that can be explored is designing routers and switches which are able to decide on forwarding/switching operations based on content. A typical application space is proactive multimedia delivery and real-time collaborative gaming.
Streamed media applications, such as video-on-demand, broadcast quality Internet television (IPTV), Internet-based telephony (VoIP), collaborative multimedia conferencing (HALO), integrated mail, text and voice chat applications (e.g., Gtalk) are becoming more and more popular and cost effective. Increase in effective throughput of links and better bandwidth handling have given a fillip to the above-mentioned applications. As networks become faster, applications tend to become more and more bandwidth hungry. As a result, there is always a case for better algorithms for QoS (Quality of Service) management.
The most popular transport mechanism for delivery of streamed audio/video content is via RTP (Real-time Transfer Protocol) encapsulated UDP (User Datagram Protocol). Generally, UDP does not guarantee reliable delivery of content unlike TCP (Transmission Control Protocol). This feature is beneficial for real-time audio/video streaming and gaming applications which are generally delay and jitter sensitive. Further, RTP encapsulation allows for multiplexing various sources of content into the same stream. The receiver-end then demultiplexes individual contributor's content and renders each of the contributors' content appropriately. Typically, the transmitter multiplexes audio and video components into the same stream and the decoder demultiplexes each of them based on an identifier, present in the RTP header. Furthermore, most of the broadcast quality IPTV solutions rely on RTP based multicast sessions for media delivery. RTP also allows multiplexing of different bit-rate video, so that, the overall quality of the decoded video can be controlled based on selecting all or a portion of these multiplexed streams.
To enable such value added services for video delivery, it is crucial to detect the presence of RTP based transmissions. Port numbers are not good indicators of whether the UDP stream is carrying RTP based transmissions. Current techniques include inspecting the payload type field following the UDP header to detect the presence of RTP. However, these techniques are not reliable and can lead to false identification of the presence of RTP.
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.